Question

What single format string can be used to print 0.0, 1.0, 0.025 ? eg given:

float vals[3] = { 0.0f, 1f, 0.025f };

for(int i=0; i < 3; i++)
    printf("%g\n", vals[i]);

desired output:

0.0
1.0
0.025

but instead get:

0
1
0.025

Have tried various width specifiers and %f vs %g but can’t get what I want.

If there’s a c++ alternative that’s fine to.

Answer 1

You can use * to tell printf the precision will come from an int argument value.

printf("%.*f\n", (vals[i] == (int)vals[i]) ? 1 : 3 ,vals[i]);

should print:

0.0
1.0
0.025